An aneurysm is a ballooning of the wall of an artery resulting from the weakening of the artery due to disease or other conditions. Left untreated, the aneurysm will frequently rupture, resulting in loss of blood through the rupture and death.
Aortic aneurysms are the most common form of arterial aneurysm and are life threatening. The aorta is the main artery which supplies blood to the circulatory system. The aorta arises from the left ventricle of the heart, passes upward and bends over behind the heart, and passes down through the thorax and abdomen. Among other arterial vessels branching off the aorta along its path, the abdominal aorta supplies two side vessels to the kidneys, the renal arteries. Below the level of the renal arteries, the abdominal aorta continues to about the level of the fourth lumbar vertebrae (or the navel), where it divides into the iliac arteries. The iliac arteries, in turn, supply blood to the lower extremities and perineal region.
It is common for an aortic aneurysm to occur in that portion of the abdominal aorta between the renal arteries and the iliac arteries. This portion of the abdominal aorta is particularly susceptible to weakening, resulting in an aortic aneurysm. Such an aneurysm is often located near the iliac arteries. An aortic aneurysm larger than about 5 cm in diameter in this section of the aorta is ominous. Left untreated, the aneurysm may rupture, resulting in rapid, and usually fatal, hemorrhaging. Typically, a surgical procedure is not performed on aneurysms smaller than 5 cm because no statistical benefit exists in performing such procedures.
Aneurysms in the abdominal aorta are associated with a particularly high mortality rate; accordingly, current medical standards call for urgent operative repair. Abdominal surgery, however, results in substantial stress to the body. Although the mortality rate for an aortic aneurysm is high, there is also considerable mortality and morbidity associated with open surgical intervention to repair an aortic aneurysm. This intervention involves penetrating the abdominal wall to the location of the aneurysm to reinforce or replace the diseased section of the aortic aneurysm. A prosthetic device, typically a synthetic tube graft, is used for this purpose. The graft serves to exclude the aneurysm from the circulatory system, thus relieving pressure and stress on the weakened section of the aorta at the aneurysm.
Repair of an aortic aneurysm by surgical means is a major operative procedure. Substantial morbidity accompanies the procedure, resulting in a protracted recovery period. Further, the procedure entails a substantial risk of mortality. While surgical intervention may be indicated and the surgery carries attendant risk, certain patients may not be able to tolerate the stress of intra-abdominal surgery. It is, therefore, desirable to reduce the mortality and morbidity associated with intra-abdominal surgical intervention.
In recent years, methods have been developed to attempt to treat an aortic aneurysm without the attendant risks of intra-abdominal surgical intervention. Among them are inventions disclosed and claimed in Kornberg, U.S. Pat. No. 4,562,596 for Aortic Graft, Device and Method for Performing an Intraluminal Abdominal Aortic Aneurysm Repair; Lazarus, U.S. Pat. No. 4,787,899 for Intraluminal Graft Device, System and Method; and Taheri, U.S. Pat. No. 5,042,707 for Intravascular Stapler, and Method of Operating Same.
Although in recent years certain techniques have been developed that may reduce the stress, morbidity, and risk of mortality associated with surgical intervention to repair aortic aneurysms, none of the systems that have been developed effectively treat the aneurysm and exclude the affected section of aorta from the pressures and stresses associated with circulation. None of the devices disclosed in the references provide a reliable and quick means to reinforce an aneurysmal artery. In addition, all of the prior references require a sufficiently large section of healthy aorta surrounding the aneurysm to ensure attachment of the graft. The neck of the aorta at the cephalad end (i.e., above the aneurysm) is usually sufficient to maintain a graft's attachment means. However, when an aneurysm is located near the iliac arteries, there may be an ill-defined neck or no neck below the aneurysm. Such an ill-defined neck would have an insufficient amount of healthy aortic tissue to which to successfully mount a graft. Furthermore, much of the abdominal aorta wall may be calcified which may make it extremely difficult to attach the graft to the wall. Furthermore, the prior art does not disclose surgical devices that can be used during a surgical procedure that address these concerns. Others have developed devices that are not easily manipulated or oriented during intraluminal surgical procedures.
Methods have also been developed to use lasers to perform certain surgical procedures, particularly, Boutacoff et al., U.S. Pat. No. 5,147,354 for Mid-Infrared Laser Endoscope (hereinafter “Boutacoff”). Boutacoff is directed to a Holmium YAG (“Ho:YAG”) laser coupled to a needle tip through a flexible, fiber optical cable for performing endoscopic and arthroscopic surgery. Boutacoff only discloses use of laser energy during arthroscopic and endoscopic procedures. An embodiment of the present invention, in contrast, is directed to catheter-based surgical procedures. In arthroscopic and endoscopic procedures, tissue is ablated for the purpose of removing excess tissue. The tissue must be distended by gas or fluids to prevent burning or smoking during the procedure. In Boutacoff, a fluid field is maintained to flush the knee, thereby reducing the amount of smoke produced by the ablation procedure. The fluid field is necessary to distend the tissue and to improve visualization during the procedure.
In contrast, an embodiment of the present invention is not directed to ablating tissue with laser energy, but rather to penetrating tissue or other components to create treatment specific holes therein. Because tissue is not ablated or removed as in Boutacoff, burning and smoking are not problems, and thus, there is no need to maintain a fluid field. Hence, an embodiment of the present invention is not limited and possesses none of the needs of Boutacoff, mainly ablation for removing excess tissue and maintenance of a fluid field. Rather, an embodiment of the present invention is a novel application of laser technology for the performance of surgical procedures.
It is an advantage of an embodiment of the present invention to provide a method for creating a treatment specific hole at a procedure specific area with a laser fiber assembly. It is another advantage of an embodiment of the present invention to provide a method for repairing tissue by creating a treatment specific hole in the tissue with a laser fiber assembly and inserting a fastener through the hole. It is yet another advantage of an embodiment of the present invention to provide a method for repairing an aneurysm by creating a treatment specific hole in a surgical component and a vessel wall with a laser fiber assembly and inserting a fastener through the hole.
Additional advantages of embodiments of the invention are set forth, in part, in the description that follows and, in part, will be apparent to one of ordinary skill in the art from the description and/or from the practice of the invention.